


[Not] My Fault

by AzureNight



Category: Undertale (Video Game)
Genre: Angst, Fluff, Fluff and Angst, M/M
Language: English
Status: Completed
Published: 2018-10-08
Updated: 2018-10-08
Packaged: 2019-07-28 06:31:13
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,977
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16236116
Author URL: https://archiveofourown.org/users/AzureNight/pseuds/AzureNight
Summary: Could you actually write a Drabble of bad sans poly with the forgetful existence HC? "Don't freak about it dude. Calm down it's okay." Fluff or angst it's up to you-@mastermind-mokieWell, this got slightly out of hand, didn't it.





	[Not] My Fault

**Author's Note:**

> So, I got a request about this headcanon that I posted eons ago on my tumblr, and now I'm finally posting it! Took forever to write but have your fluff! And angst, because it's me what did you expect.

“Hey, Nightmare, don’t freak out about it dude, everything’s gonna be okay,” Dust said, looking, concerned, at his Boss and boyfriend, who’d been pacing worriedly along the corridor, unable to stay still, glancing at the door to the ER every minute. Being in his weaker form, to make sure no one recognised him, was grating on his nerves and making him more nervous, and it’s wasn’t helping matters.

 

“No, it won’t! This is my fault.” Nightmare sounded incredibly upset, and Dust supposed he would be, considering what had happened in-battle; he’d dissociated, completely lost his sense of self and been open to any manipulation, and Horror and Error were in the ER as a result. Dream seemed to be able to snap Nightmare out of it, and had been absolutely mad at Ink for taking advantage of Nightmare in that way and making him harm his own boyfriends, Error and Horror, to the point they were rushed to Dream’s hospital at once.

 

“It’s not your fault, blame Ink,” Dust said, getting up and placing a hand on Nightmare’s shoulder, so they were face to face, and kissed him gently.

 

The door to the waiting room opened, making the two turn their heads, as Dream slipped in silently, a tight smile on his face. Dust regarded him warily, eyes narrowed, and tried to pull Nightmare closer to him, but Nightmare ended up pulling away to hug his brother instead.

 

“I’m so sorry Night,” Dream murmured, too quietly for Dust to hear, but he could read lips. Everything that came out of Dream’s mouth seemed to be an apology of sorts, but when they started talking about other, more private things, he averted his eyes, passing the time instead by looking at Papyrus and reading his lips to try and have a conversation.

 

Dream and Nightmare sat some way away from Dust, talking in low voices. He kept an eye on the two, not entirely trusting of Dream, but Nightmare wasn’t pacing anymore, which was a good point in his book.

 

Eventually, Dream left, giving Nightmare’s hand a reassuring squeeze, and a smile, before exiting the room, making Nightmare gaze at the door longingly, then move to sit next to Dust again.

 

“You two sure are close for being on opposing sides,” Dust remarked, not without a hint of jealousy.

 

“He was the only one who understood the dissociation,” Nightmare offered by way of explanation, making Dust frown.

 

“You’ve got me, Horror, Killer, Cross, and Error though,” he pointed out, hurt colouring his tone. Were they not enough?

 

Nightmare nodded. “Yes, but all of you have been with me for perhaps five years, and I’ve lived with the dissociation for quite a bit longer than five years. Dream helped me and I helped him for a long time.”

 

Just then, the door to the ER opened, and a nurse came out.

 

“Are they okay?” was the first thing that Nightmare asked, getting up.

 

“They’ll live. Whoever attacked them was incredibly powerful and the attack has probably traumatised them however, and you must, if possible, prevent any interaction, or, mentally, they could be very badly impacted,” the nurse informed them. There was no malice in her tone, but Nightmare’s expression crumpled into one of guilt anyway.

 

“You may visit them now, we’ve put them in rooms 107 and 108.” The nurse walked back into the ER having said that, and Dust got up and walked over to Nightmare, taking his hand in his own, and giving him a peck on the cheek.

 

“Come on, let’s go see them. They’re probably waiting to see you… Nightmare?” Dust asked, and sighed at the vacant look in Nightmare’s eyes. “Hey, snap out of it, Your name is Nightmare and you have to do shit.”

 

“My name… my name’s not Nightmare, though?” Nightmare looked adorably confused, making Dust want to kiss him, but he refrained from doing so.

 

“You know what, never mind, we have to go see our boyfriends now. Horror and Error.” Dust had hoped that the names would prompt a reaction, but nothing. He pulled Nightmare into the room where Error was first, knocking, though getting no reply, and going in.

 

Nightmare’s upset gasp and downcast eyes told Dust he now remembered. “Error?” he asked, looking him over for any immediately visible injuries, but there were none. Error himself was in a medically induced coma, the IV drip in his arm preventing him from waking up.

 

Dust longed to rip it out, and he could tell Nightmare did too - what if the IV was poisoned? They could trust no one - but they kept their distance from it. Dream owned the hospital and Nightmare trusted Dream, which made the hospital, at the very least, somewhat trustworthy in Dust’s eyes. They were still getting out at the earliest opportunity though.

 

“I’m sorry,” Nightmare whispered, looking at the sleeping destroyer with guilty eyes. Had Error woken up, Dust was sure he would have insisted it wasn’t Nightmare’s fault. Error slept on.

 

“Do you want to see Horror too?” Dust asked. “Remember, this isn’t your fault. Blame Ink.” Dust spat Ink’s name with so much contempt Nightmare could imagine himself gaining a power boost from it.

 

“If seeing him will make you feel worse, we’re not going,” Dust said. Neither Error nor Horror would want Nightmare to feel guilty about it.

 

Nightmare shook his head. “I want to see him, he’s just in the room next door anyway. No point in not going,” he said, taking one last glance at Error before turning towards the door and walking out of the room, Dust following him, across the corridor and into Horror’s hospital room.

 

When Nightmare knocked, he actually got a response - “It’s three AM, this better be important!” - signalling that Horror was awake, a relief really, as it meant his injuries weren’t severe enough to warrant a medical coma for him to heal properly.

 

Horror grinned when the two came in, giving a wave with his unbroken arm. “Hiya Night, Dust-pan,” he said, making Dust narrow his eyes at the pet name and sigh silently in exasperation, though there was a small smile tugging at his lips. Dust would have started arguing with Horror if he hadn’t seen Nightmare smiling slightly. Horror was more intelligent than most people gave him credit for.

 

“Night, when can I get out of here? I’m bored,” Horror whined, making Nightmare roll his eyes.

 

“You’re injured and you’re only getting out once Dream gives you the okay,” he said, making Horror’s eyes widen in surprise, and a little wariness.

 

“Dream’s trustworthy, don’t worry,” Dust assured Horror, though he didn’t quite believe those words himself. “Apparently he and Nightmare have an exclusive “we forget we exist” club that’s existed for five hundred years because they’re both old as shit.”

 

Nightmare huffed, crossing his arms. “I’m not  _ that _ old,” he insisted, glaring at Dust, who only grinned back.

 

“Nightmare you’re five hundred and whatever you’re old,” Horror said, making Nightmare pout at him, though the playfulness in his expression seemed oddly forced making Dust sigh internally.

 

_ He’s still beating himself up about it,  _ he thought sadly, noticing that Horror stopped joking too.

 

“Seriously Boss, don’t beat yourself up. Beat Ink up instead,” Horror said, failing to be serious, though he frowned and sobered up fast when Nightmare didn’t laugh or smile at all. “Boss I don’t care about these pathetic little injuries, they’re nothing.” That may have been a little exaggeration on his part. “I’ve been in hospital loads of times, it’s fine. But for real go slap Ink because he’s a little bitch who deserves it.”

 

“I think Dream already did that but I’ll gladly do it again. It’s three AM though, I should let you sleep,” Nightmare said, tone undecipherable, but Dust was willing to bet he was feeling guilty over keeping Horror up.

 

“Yeah sure. Bye Boss! Make sure you get some sleep too,” Horror said, as Nightmare and Dust exited the hospital room.

 

“Do you feel any better after seeing them alive and safe?” Dust asked Nightmare, walking down the corridor, hand in hand.

 

“Not really,” Nightmare admitted, keeping his eyes fixed on the floor, never meeting Dust’s eyes as he spoke. “I really just want to sleep and forget this ever happened.”

 

“Then let’s do that,” Dust said, squeezing Nightmare’s hand reassuringly. “Come on, Cross and Killer have gotta be worried at this point. Or asleep.”

 

Nightmare nodded, smiling at Dust, though he kept his eyes averted. “At least back home we won’t be bothered,” he replied, readying to snap and disappear, when someone came into view.

 

“What the hell are  _ you _ doing here,” Nightmare said coldly, more a threat than a question somehow, making Ink pull a face, and put his hands up in a mock surrender.

 

“Geez, you’re unfriendly,” he commented rudely. “I’m here because this is my boyfriend’s hospital and I’m looking for him. Actually have you seen Dream? I think you ended up hurting him and he was around here trying to hide his injuries.”

 

Nightmare was furious until he heard about Dream, and then he was guilty, self-deprecation flashing across his face.

 

“What- How badly was he hurt?” Nightmare asked, making Ink shrug somewhat dismissively.

 

“Eh, I think he complained about magic drain and some damage to his soul. A few ribs came off too.” Ink gestured to Dust. “Probably deserves it for defending the likes of him-”

 

In less than a second, Nightmare was in his fully corrupted form, single eye blazing cyan, aura murderous. A tentacle was wrapped around Ink’s neck, and it lifted him off the ground, making him choke and claw at it desperately.

 

“What on earth- Nightmare stop!”

 

All heads turned to the newcomer, and Nightmare tentatively withdrew his tentacle, though the corruption didn’t fade. Dust knew he wore it like armour.

 

“Well, that was an overreaction,” Ink commented, rubbing at his neck, eyeing Nightmare warily, making Nightmare narrow his eyes and tense, and Dust reach for his knife at his belt.

 

“I’m willing to bet you started it,” Dream said, displeased gaze fixed on Ink.

 

Ink rolled his eyes, and put an offended hand to his chest in melodramatic fashion. “You’d side with him over me?” he asked, mock outrage in his voice.

 

“After the shit you pulled? Yes. Every time.” Joking as though Ink may have been, Dream was dead serious.

 

“Look, I didn’t say anything bad, only that, ya know, he fucked up your soul and did damage to your ribs so they got cracked, which you pretended never happened so you could spend magic you couldn’t afford to give away healing him and ended up hurting yourself more, that’s all,” Ink said innocently. “You know as your closest living relative he does deserve to know this stuff.”

 

Now Dream looked downright murderous. Nightmare looked very small in contrast, the corruption fading.

 

“Ink, know when to shut the  _ fuck _ up,” Dream snapped coldly. “Head back to your Doodlesphere and stop bothering us.”

 

“Why would you heal me if you were hurt? That would damage your magic core even more,” Nightmare said, sounding angry in the way he always did when anyone he cared for put him over themself.

 

“Not important, I’ll tell you later-”Dream started, before being cut off by Nightmare.

 

“I do think it’s important, actually,” he stated, looking Dream straight in the eye.

 

“Then I’ll tell you later, in private,” Dream replied evenly. “For now, you’re in a bad mental state and should go home because Killer and Cross will be worried for you if the only person who’s assured them you’re alive is me.”

 

The guardians glared at each other, neither willing to back down. In the background, Ink wandered off, bored by the interaction. Dust coughed, interrupting the two guardians’ staring contest in favour of looking at him expectantly.

 

“Dream has a point.”

 

Immediately Nightmare let out a noise of protest and Dream smiled victoriously.

 

“Nightmare, for real, it’s coming on four AM and you’ve not slept in over 24 hours. You and Dream can have brunch or something tomorrow to chat about this,” Dust reasoned. “Besides, I’m also tired and want to go home, and there’s no way I’m leaving you here alone, so you’d be making me stay up later,” he added. Nightmare only sighed at the overt manipulation.

 

“Go home, meet me here tomorrow at 12, and then we can talk,” Dream said, tone definitive. Then he blinked, three or four times, and shook his head ever so slightly.

 

Nightmare sighed, turning his head to face Dust. “Are you against having Dream over? Because he just dissociated and I’m not leaving him here with Ink around.”

 

Dust shrugged. “Let’s have him over for a sleepover or whatever then. But let’s go  _ now _ because I wasn’t lying when I said I was tired.”

 

“Okay that works,” Nightmare said, nodded, and grabbed Dream’s hand, minutely flaring his aura as he did it; in his dissociative state, Dream would recognise the aura as safety and come with him without protest.

 

Dust snapped his fingers, disappearing from the hospital and landing in the castle, Nightmare and Dream but a split-second behind. In front of them, on the couch, Killer was dozing, phone in hand, obviously waiting for news earlier though having fallen asleep.

 

“Dust, do you want to take Killer to his room? Dream can sleep with me tonight, it’s not like I don’t have the space,” Nightmare said. Dream looked ready to collapse; absolutely exhausted. Considering he’d been expending energy he didn’t have to spare for hours on end, combined with the late hour, it was to be expected.

 

Blue magic levitated Killer off the couch, as Dust nodded in agreement, his eye glowing a soft cyan, and walked away, in the direction of his room, and deposited Killer on his bed, where Cross was also curled up.

 

“Cross, you awake?” he whispered, poking his boyfriend, who nodded mutely, getting up and making room for Dust in the bed.

 

“Thanks,” Dust muttered, laying down. Cross got caught up on what had happened, and was no more trusting of Dream than Dust was, though Nightmare’s word seemed to be enough for Dust, who fell asleep in a matter of minutes once they stopped talking.

 

Cross was left unsatisfied though, and he’d slept a little earlier, so figured he could afford to lose a few hours of sleep, and crept out of the room, heading towards Nightmare’s quarters.

  
  


He pressed his head to the door, trying to see of there were any snippets of conversation between the two he could overhear, though all he heard was the sound of someone’s steady breathing, and pacing, footsteps muffled by carpet.

 

The covers rustled, and Cross could only just hear Dream whisper something, though making out the exact words was impossible. The pacing stopped, Nightmare whispering back, and they continued their quiet conversation for some time, before Cross heard the sound of someone climbing into the bed, making Cross breath a silent sigh of relief; too often, Nightmare would get no sleep at all.

 

The door, thankfully, didn’t creak when Cross leant against him, sinking down to sitting position. He didn’t particularly feel like sleeping anyway, he may as well spent the night keeping watch.

 

The door shifted and Cross jumped away from it, landing heavily on the hardwood floor, making a resounding  _ thud _ , though thankfully not too loud. When he turned, he found himself staring directly into Dream’s eyelights.

 

“You’ve been out here for an awfully long time,” Dream remarked quietly. “Aren’t you tired?”

 

Cross shook his head. “I’m worried and I can’t sleep. No way in hell.”

 

“Horror and Error will live, with no lasting impact on either of them from this. They’ll make a full recovery,” Dream assured, making Cross shruf dismissively, and an uncomfortable silence settle for a few moments.

 

“You’re not worried for Horror or Error, are you?” Dream asked, making Cross look at him sharply.

 

“Of course I am,” he hissed defensively, taking Dream’s comment as an attack against him.

 

“It’s not what’s on your mind right now though,” Dream countered calmly. “You don’t trust me, any of you, that much is obvious, not that I blame you. You’re out here worried that I’ll do something to Nightmare.”

 

Cross glared at Dream, frustration rising in him at Dream’s perceptiveness. “Great, so you know what I want. You gonna leave now?” he asked bluntly, not even bothering the fact he wanted Dream gone.

 

“No. Nightmare  _ will _ freak out if I disappear with no warning in the middle of the night,” Dream explained, not that Cross didn’t know all this anyway, what with Nightmare’s protective tendencies, though it didn’t mean he liked it or that he wasn’t going to argue against Dream’s presence in the castle.

 

“Stop being stubborn. I’m not leaving until you do, and if I stay up Nightmare will be sad. You’ll be at fault for-”

 

“Stop being an arse and fuck off to bed.”

 

Both Cross and Dream started at the new, louder voice. Nightmare looked decidedly unimpressed with them.

 

“It is  _ really fucking late _ and I want to sleep without you hovering outside my door,” he told Cross. “I trust Dream.”

 

Cross pouted unhappily but didn’t say anything against it, knowing when to give up. “Fine.”

 

That seemed enough for Nightmare, who turned back to his room, headed for his bed. Dream smirked victoriously, a little childishly, making Cross roll his eyes and flip him off, before walking away in a huff.

 

“Your boyfriend is super mature,” Dream remarked, closing the door behind him as he walked back into Nightmare’s bedroom and getting under the covers. Nightmare flicked him on the forehead.

 

“I meant what I said,  _ sleep _ ,” he grumbled.

 

“Okay. Night night, Nightlight,” Dream hummed, grinning when he heard Nightmare’s exasperated sigh.

 

“Goodnight Dream.”


End file.
